The function of the Molecular Biology Core is to provide the Center for Study of Opioid Receptors and Drugs of Abuse (CSORDA) with resources related to the use of recombinant DNA and adjunct methodologies. In broad terms, these resources will be used by members of the various Scientific Components for experiments designed to analyze and characterize genes encoding members of the opioid receptor family and their peptide ligands. The Molecular Biology Core Director and staff will support CSORDA Components by designing and implementing site-directed mutagenesis protocols, genetically engineer chimeric and epitope-tagged proteins, construct eucaryotic viral and plasmid-based expression constructs, and genotype transgenic and mutant mice strains. In addition, the Molecular Biology Core will consult with the Principle Investigators and Core supervisors on overall strategies for individual projects and provide training and support in specific molecular techniques to students, technicians, visiting scientists, and collaborators working outside the Center.